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| 1 | namespace Semantic.Symbols is | |
| 2 | use IO.Std; | |
| 3 | ||
| 4 | use System.Text.StringBuilder; | |
| 5 | ||
| 6 | use IoC; | |
| 7 | use Logging; | |
| 8 | use Source; | |
| 9 | ||
| 10 | use IR.Values.Value; | |
| 11 | ||
| 12 | use Types.Type; | |
| 13 | ||
| 14 | // Per-yield bookkeeping recorded by yield IL emission. | |
| 15 | // The resumption label is placed immediately after the | |
| 16 | // `ret` that suspends the generator; entry-dispatch jumps | |
| 17 | // here when MoveNext re-enters in this state. | |
| 18 | class STATE_LABEL is | |
| 19 | state: int; | |
| 20 | label: IR.LABEL; | |
| 21 | ||
| 22 | init(state: int, label: IR.LABEL) is | |
| 23 | self.state = state; | |
| 24 | self.label = label; | |
| 25 | si | |
| 26 | si | |
| 27 | ||
| 28 | // State held on a generator function symbol: the synthesised | |
| 29 | // frame class, the running state-number counter, the recorded | |
| 30 | // (state, resumption-label) pairs for entry-dispatch emission. | |
| 31 | // Lives as a non-null field on each *_GENERATOR_* function; | |
| 32 | // checked-for via `state_machine_for(...)`. | |
| 33 | class STATE_MACHINE is | |
| 34 | function: Function public; | |
| 35 | ||
| 36 | _frame: STATE_MACHINE_FRAME?; | |
| 37 | _next_state: int; | |
| 38 | _yield_labels: Collections.LIST[STATE_LABEL]; | |
| 39 | ||
| 40 | init(function: Function) is | |
| 41 | self.function = function; | |
| 42 | ||
| 43 | _next_state = 1; | |
| 44 | _yield_labels = Collections.LIST[STATE_LABEL](); | |
| 45 | si | |
| 46 | ||
| 47 | // Lazy: the frame class is materialised on first access, | |
| 48 | // pulling its element type from the (now-resolved) function | |
| 49 | // return type. Returns null only if the return type is not | |
| 50 | // an `Iterable[T]` / `Iterator[T]` — which is an upstream | |
| 51 | // diagnostic, not something the frame can recover from. | |
| 52 | frame: STATE_MACHINE_FRAME? is | |
| 53 | if !_frame? then | |
| 54 | let element_type = _extract_element_type(); | |
| 55 | ||
| 56 | if !element_type? then | |
| 57 | return null; | |
| 58 | fi | |
| 59 | ||
| 60 | _frame = STATE_MACHINE_FRAME(function.owner!, function, element_type); | |
| 61 | fi | |
| 62 | ||
| 63 | return _frame; | |
| 64 | si | |
| 65 | ||
| 66 | _extract_element_type() -> Type? is | |
| 67 | if !function.return_type? then | |
| 68 | return null; | |
| 69 | fi | |
| 70 | ||
| 71 | let lookup = IoC.CONTAINER.instance.innate_symbol_lookup; | |
| 72 | ||
| 73 | // A generator returns Pipe[T]; extract T from the Pipe | |
| 74 | // itself (self-match), not from its Iterable[T] base — the | |
| 75 | // base carries Pipe's own type parameter, not the concrete | |
| 76 | // element type the return is constructed over. When Pipe is | |
| 77 | // unavailable (no runtime referenced) fall back to the bare | |
| 78 | // Iterable[T] / Iterator[T] forms. | |
| 79 | let pipe = lookup.get_unspecialized_pipe_type(); | |
| 80 | ||
| 81 | if pipe? then | |
| 82 | return TYPE_ARGUMENT_EXTRACTOR.extract(function.return_type, pipe); | |
| 83 | fi | |
| 84 | ||
| 85 | let candidates = Collections.LIST[Type](); | |
| 86 | candidates.add(lookup.get_unspecialized_iterator_type()); | |
| 87 | candidates.add(lookup.get_unspecialized_iterable_type()); | |
| 88 | ||
| 89 | return TYPE_ARGUMENT_EXTRACTOR.extract_from_any(function.return_type, candidates); | |
| 90 | si | |
| 91 | ||
| 92 | allocate_state() -> int is | |
| 93 | let n = _next_state; | |
| 94 | ||
| 95 | _next_state = _next_state + 1; | |
| 96 | ||
| 97 | return n; | |
| 98 | si | |
| 99 | ||
| 100 | record_label(state: int, label: IR.LABEL) is | |
| 101 | _yield_labels.add(STATE_LABEL(state, label)); | |
| 102 | si | |
| 103 | ||
| 104 | yield_labels: Collections.Iterable[STATE_LABEL] => _yield_labels; | |
| 105 | ||
| 106 | // Install / uninstall gen_type_override on every type- | |
| 107 | // parameter visible inside the body so IR.Values built by | |
| 108 | // compile-expressions render type-parameter references as | |
| 109 | // `!N` (class-level on the frame, which is what MoveNext | |
| 110 | // sees) rather than `!!N` (method-level on the original | |
| 111 | // function). See `STATE_MACHINE_TYPE_PARAMS` for details. | |
| 112 | install_body_emission_overrides() is | |
| 113 | STATE_MACHINE_TYPE_PARAMS.walk_install(function, true); | |
| 114 | si | |
| 115 | ||
| 116 | uninstall_body_emission_overrides() is | |
| 117 | STATE_MACHINE_TYPE_PARAMS.walk_install(function, false); | |
| 118 | si | |
| 119 | ||
| 120 | // Type arguments to pass at `newobj` construction time, in | |
| 121 | // the same canonical order the frame captures them. See | |
| 122 | // `STATE_MACHINE_TYPE_PARAMS` for details. | |
| 123 | get_construction_type_arguments() -> Collections.List[Type]? => | |
| 124 | STATE_MACHINE_TYPE_PARAMS.construction_type_arguments(function); | |
| 125 | si | |
| 126 | ||
| 127 | // Synthesised class holding a generator's state machine. | |
| 128 | // Implements `Iterator[T]` (so the ienumerable/ienumerator | |
| 129 | // boilerplate emitters fire automatically). Members: `$state` | |
| 130 | // (0=initial, -1=done, N=resumption point), `$current` (last | |
| 131 | // yielded value), `$outer_self` (instance-only). The Iterator | |
| 132 | // methods (MoveNext/get_Current/Dispose/Reset) are hand-emitted | |
| 133 | // in generate_il rather than declared ghūl-side. | |
| 134 | class STATE_MACHINE_FRAME: STATE_MACHINE_FRAME_BASE is | |
| 135 | _next_id: int static; | |
| 136 | ||
| 137 | _element_type: Type; | |
| 138 | ||
| 139 | // Null until declare() runs; outer-self stays null past | |
| 140 | // declare() for static and global generators. | |
| 141 | _state_field: Field?; | |
| 142 | _current_field: Field?; | |
| 143 | _outer_self_field: Field?; | |
| 144 | _constructor: Method?; | |
| 145 | ||
| 146 | element_type: Type => _element_type; | |
| 147 | ||
| 148 | // The element type rewritten into the frame class's scope — | |
| 149 | // for use when hand-emitting IL strings that reference the | |
| 150 | // element type inside the class body (e.g. accessor method | |
| 151 | // signatures). Renders as `!N` (class-level) for a generic | |
| 152 | // generator, same as `_element_type` for a non-generic one. | |
| 153 | class_element_type: Type => _class_relative(_element_type); | |
| 154 | // Non-null once declare() has run. | |
| 155 | state_field: Field => _state_field!; | |
| 156 | current_field: Field => _current_field!; | |
| 157 | constructor: Method => _constructor!; | |
| 158 | ||
| 159 | outer_self_field: Field? => _outer_self_field; | |
| 160 | ||
| 161 | next_id: int static is | |
| 162 | let result = _next_id; | |
| 163 | _next_id = _next_id + 1; | |
| 164 | return result; | |
| 165 | si | |
| 166 | ||
| 167 | init(owner: Scope, owning_function: Function, element_type: Type) is | |
| 168 | let owner_owner: Scope mut; | |
| 169 | ||
| 170 | if isa Symbol(owner) then | |
| 171 | let owner_symbol = owner; | |
| 172 | owner_owner = owner_symbol.owner!; | |
| 173 | else | |
| 174 | owner_owner = owner; | |
| 175 | fi | |
| 176 | ||
| 177 | super.init( | |
| 178 | LOCATION.internal, | |
| 179 | LOCATION.internal, | |
| 180 | owner_owner, | |
| 181 | "$StateMachine_{owning_function.name}_{next_id}", | |
| 182 | owner, | |
| 183 | owning_function | |
| 184 | ); | |
| 185 | ||
| 186 | _element_type = element_type; | |
| 187 | ||
| 188 | _argument_fields = Collections.LIST[Field](); | |
| 189 | ||
| 190 | set_type(Types.NAMED(self)); | |
| 191 | si | |
| 192 | ||
| 193 | // Argument fields, paired with their LOCAL_ARGUMENT source | |
| 194 | // symbols. The constructor takes one parameter per argument | |
| 195 | // (in the same order as the user function's parameters) and | |
| 196 | // stores each into the matching field; the body's IR for a | |
| 197 | // parameter load routes through `state_machine_field` and | |
| 198 | // becomes ldarg.0; ldfld instead of ldarg. | |
| 199 | _argument_fields: Collections.LIST[Field]; | |
| 200 | ||
| 201 | argument_fields: Collections.Iterable[Field] => _argument_fields; | |
| 202 | ||
| 203 | // Declare the frame's members lazily — called by IL emission. | |
| 204 | // Fields and constructor get real Symbol entities so reference | |
| 205 | // emission (ldfld, stfld, newobj) routes through the existing | |
| 206 | // SYMBOL_LOADER paths. The Iterator[T] / Iterable[T] methods | |
| 207 | // are NOT declared as ghūl symbols — their IL is emitted by | |
| 208 | // hand in `gen_all` using the canonical .NET names. | |
| 209 | declare() is | |
| 210 | if _state_field? then | |
| 211 | return; | |
| 212 | fi | |
| 213 | ||
| 214 | let listener = IoC.CONTAINER.instance.symbol_definition_locations; | |
| 215 | ||
| 216 | declare_captured_type_params(listener); | |
| 217 | ||
| 218 | let int_type = IoC.CONTAINER.instance.innate_symbol_lookup.get_int_type(); | |
| 219 | ||
| 220 | let state_field = Symbols.INSTANCE_FIELD(LOCATION.internal, self, "$state"); | |
| 221 | state_field.set_type(int_type); | |
| 222 | declare(LOCATION.internal, state_field, listener); | |
| 223 | _state_field = state_field; | |
| 224 | ||
| 225 | let current_field = Symbols.INSTANCE_FIELD(LOCATION.internal, self, "$current"); | |
| 226 | current_field.set_type(_class_relative(_element_type)); | |
| 227 | declare(LOCATION.internal, current_field, listener); | |
| 228 | _current_field = current_field; | |
| 229 | ||
| 230 | let ctor_argument_names = Collections.LIST[string](); | |
| 231 | let ctor_argument_types = Collections.LIST[Type](); | |
| 232 | ||
| 233 | // Instance generators carry a reference to the user's | |
| 234 | // enclosing instance so the body's `self` / instance | |
| 235 | // field access can be redirected via `ldarg.0; ldfld | |
| 236 | // _outer_self`. The outer method passes `this` to the | |
| 237 | // .ctor as the first argument. | |
| 238 | if owning_function.is_instance /\ owning_function.owner? /\ isa Classy(owning_function.owner) then | |
| 239 | let outer_classy = cast Classy?(owning_function.owner)!; | |
| 240 | let self_type = outer_self_type(outer_classy); | |
| 241 | ||
| 242 | let outer_self_field = Symbols.INSTANCE_FIELD(LOCATION.internal, self, "$outer_self"); | |
| 243 | outer_self_field.set_type(self_type); | |
| 244 | declare(LOCATION.internal, outer_self_field, listener); | |
| 245 | _outer_self_field = outer_self_field; | |
| 246 | ||
| 247 | ctor_argument_names.add("$outer_self"); | |
| 248 | ctor_argument_types.add(self_type); | |
| 249 | fi | |
| 250 | ||
| 251 | if owning_function.argument_names.count > 0 then | |
| 252 | for arg_name in owning_function.argument_names do | |
| 253 | let local = cast Symbols.LOCAL_ARGUMENT?(owning_function.find_direct(arg_name)); | |
| 254 | ||
| 255 | if !local? then | |
| 256 | continue; | |
| 257 | fi | |
| 258 | ||
| 259 | let arg_field_type = _class_relative(local.type!); | |
| 260 | ||
| 261 | let arg_field = Symbols.INSTANCE_FIELD(LOCATION.internal, self, "$arg_{arg_name}"); | |
| 262 | arg_field.set_type(arg_field_type); | |
| 263 | declare(LOCATION.internal, arg_field, listener); | |
| 264 | ||
| 265 | _argument_fields.add(arg_field); | |
| 266 | ||
| 267 | local.state_machine_field = arg_field; | |
| 268 | ||
| 269 | ctor_argument_names.add(arg_name); | |
| 270 | ctor_argument_types.add(arg_field_type); | |
| 271 | od | |
| 272 | fi | |
| 273 | ||
| 274 | let ctor = Symbols.INSTANCE_METHOD(LOCATION.internal, LOCATION.internal, self, "init", self); | |
| 275 | ctor.set_arguments(ctor_argument_names, ctor_argument_types); | |
| 276 | ctor.set_void_return_type(); | |
| 277 | declare(LOCATION.internal, ctor, listener); | |
| 278 | _constructor = ctor; | |
| 279 | ||
| 280 | // Ancestors — Object + Iterable[T]/Iterator[T] so the | |
| 281 | // standard boilerplate emitters (gen_extends / | |
| 282 | // gen_implements, ienumerable/ienumerator bridges) fire. | |
| 283 | // Interface args use the frame's own T so the implements | |
| 284 | // clause emits `IEnumerable<!N>`. | |
| 285 | let lookup = IoC.CONTAINER.instance.innate_symbol_lookup; | |
| 286 | let class_relative_element = _class_relative(_element_type); | |
| 287 | ||
| 288 | add_ancestor(lookup.get_object_type()); | |
| 289 | add_ancestor(_construct_specialised(lookup.get_unspecialized_iterable_type(), class_relative_element)); | |
| 290 | add_ancestor(_construct_specialised(lookup.get_unspecialized_iterator_type(), class_relative_element)); | |
| 291 | ||
| 292 | // If the declared return type is a *proper* subtype of | |
| 293 | // Iterable[T] / Iterator[T] — a richer iterable trait such | |
| 294 | // as Ghul.Pipes.Pipe[T] — implement it too, so the outer | |
| 295 | // method can return the state machine directly as that | |
| 296 | // type and the caller gets the trait's members (the pipe | |
| 297 | // combinators) for free. A return type that is exactly | |
| 298 | // Iterable[T] or Iterator[T] is already covered above; | |
| 299 | // find_ancestor does not self-match, so it is not re-added. | |
| 300 | let return_type = owning_function.return_type; | |
| 301 | ||
| 302 | if | |
| 303 | return_type? /\ | |
| 304 | return_type.is_settled /\ | |
| 305 | ( | |
| 306 | return_type.find_ancestor(lookup.get_unspecialized_iterable_type())? \/ | |
| 307 | return_type.find_ancestor(lookup.get_unspecialized_iterator_type())? | |
| 308 | ) | |
| 309 | then | |
| 310 | add_ancestor(_class_relative(return_type)); | |
| 311 | fi | |
| 312 | si | |
| 313 | ||
| 314 | _construct_specialised(unspecialized: Type, type_arg: Type) -> Type is | |
| 315 | let classy = cast Symbols.Classy?(unspecialized.symbol.unspecialized_symbol)!; | |
| 316 | ||
| 317 | let args = Collections.LIST[Type](); | |
| 318 | args.add(type_arg); | |
| 319 | ||
| 320 | return Types.GENERIC(LOCATION.internal, classy, args); | |
| 321 | si | |
| 322 | si | |
| 323 | ||
| 324 | // Free helper: returns the STATE_MACHINE held by any of the three | |
| 325 | // generator function forms, or null if `f` is a plain function. | |
| 326 | state_machine_for(f: Function?) -> STATE_MACHINE? is | |
| 327 | if !f? then | |
| 328 | return null; | |
| 329 | fi | |
| 330 | ||
| 331 | if isa STATIC_GENERATOR_METHOD(f) then | |
| 332 | return f.state_machine; | |
| 333 | fi | |
| 334 | ||
| 335 | if isa INSTANCE_GENERATOR_METHOD(f) then | |
| 336 | return f.state_machine; | |
| 337 | fi | |
| 338 | ||
| 339 | if isa GLOBAL_GENERATOR_FUNCTION(f) then | |
| 340 | return f.state_machine; | |
| 341 | fi | |
| 342 | ||
| 343 | return null; | |
| 344 | si | |
| 345 | ||
| 346 | // Concrete generator-function forms — thin extensions of the | |
| 347 | // existing function/method classes that additionally carry a | |
| 348 | // STATE_MACHINE bookkeeping object. Each form differs only in | |
| 349 | // its CLR-level signature shape (instance, static, global). | |
| 350 | ||
| 351 | class STATIC_GENERATOR_METHOD: STATIC_METHOD is | |
| 352 | state_machine: STATE_MACHINE public; | |
| 353 | ||
| 354 | describe_kind(context: DESCRIBE_CONTEXT) -> string? => | |
| 355 | "class generator"; | |
| 356 | ||
| 357 | gen_access(buffer: System.Text.StringBuilder) is | |
| 358 | _gen_underscore_access(buffer); | |
| 359 | si | |
| 360 | ||
| 361 | is_accessible_to(accessor: Classy?) -> bool => | |
| 362 | _underscore_is_accessible_to(accessor); | |
| 363 | ||
| 364 | init(location: LOCATION, span: LOCATION, owner: Scope, name: string, enclosing_scope: Scope) is | |
| 365 | super.init(location, span, owner, name, enclosing_scope); | |
| 366 | ||
| 367 | state_machine = STATE_MACHINE(self); | |
| 368 | si | |
| 369 | si | |
| 370 | ||
| 371 | class INSTANCE_GENERATOR_METHOD: INSTANCE_METHOD is | |
| 372 | state_machine: STATE_MACHINE public; | |
| 373 | ||
| 374 | describe_kind(context: DESCRIBE_CONTEXT) -> string? => | |
| 375 | "generator"; | |
| 376 | ||
| 377 | gen_access(buffer: System.Text.StringBuilder) is | |
| 378 | _gen_underscore_access(buffer); | |
| 379 | si | |
| 380 | ||
| 381 | is_accessible_to(accessor: Classy?) -> bool => | |
| 382 | _underscore_is_accessible_to(accessor); | |
| 383 | ||
| 384 | init(location: LOCATION, span: LOCATION, owner: Scope, name: string, enclosing_scope: Scope) is | |
| 385 | super.init(location, span, owner, name, enclosing_scope); | |
| 386 | ||
| 387 | state_machine = STATE_MACHINE(self); | |
| 388 | si | |
| 389 | ||
| 390 | // Inside the body, `self` and instance-member access go via | |
| 391 | // the state-machine frame's _outer_self field rather than | |
| 392 | // ldarg.0 (which would point at the state machine itself). | |
| 393 | // Force the frame's declare() so _outer_self_field is | |
| 394 | // available — compile-expressions reaches here before | |
| 395 | // _pre_generator_function (the regular declare site) but | |
| 396 | // after return-type resolution, so the lazy frame creation | |
| 397 | // succeeds. | |
| 398 | load_self(location: LOCATION, loader: SYMBOL_LOADER) -> Value is | |
| 399 | let frame = state_machine.frame; | |
| 400 | ||
| 401 | if frame? then | |
| 402 | frame.declare(); | |
| 403 | ||
| 404 | let outer_self_field = frame.outer_self_field; | |
| 405 | ||
| 406 | if outer_self_field? then | |
| 407 | let context = IoC.CONTAINER.instance.symbol_table.current_instance_context; | |
| 408 | if context? then | |
| 409 | return IR.Values.Load.OUTER_SELF(context, context.type, outer_self_field); | |
| 410 | fi | |
| 411 | fi | |
| 412 | fi | |
| 413 | ||
| 414 | return super.load_self(location, loader); | |
| 415 | si | |
| 416 | si | |
| 417 | ||
| 418 | // A generator declared in a trait body. Always has a body — the | |
| 419 | // generator classification comes from finding `yield` in one — so | |
| 420 | // there is no abstract counterpart, and it is a default trait | |
| 421 | // method for inheritance purposes like any other bodied trait | |
| 422 | // member. | |
| 423 | class DEFAULT_TRAIT_GENERATOR_METHOD: INSTANCE_GENERATOR_METHOD is | |
| 424 | describe_kind(context: DESCRIBE_CONTEXT) -> string? => | |
| 425 | "default trait generator"; | |
| 426 | ||
| 427 | is_default_trait_method: bool => true; | |
| 428 | ||
| 429 | init(location: LOCATION, span: LOCATION, owner: Scope, name: string, enclosing_scope: Scope) is | |
| 430 | super.init(location, span, owner, name, enclosing_scope); | |
| 431 | si | |
| 432 | ||
| 433 | try_instance_override_me(into: Classy, overrider: Function, logger: Logger) is | |
| 434 | super.try_instance_override_me(into, overrider, logger); | |
| 435 | ||
| 436 | _check_ineffective_trait_override(into, overrider, logger); | |
| 437 | si | |
| 438 | si | |
| 439 | ||
| 440 | class GLOBAL_GENERATOR_FUNCTION: GLOBAL_FUNCTION is | |
| 441 | state_machine: STATE_MACHINE public; | |
| 442 | ||
| 443 | describe_kind(context: DESCRIBE_CONTEXT) -> string? => | |
| 444 | "global generator"; | |
| 445 | ||
| 446 | init(location: LOCATION, span: LOCATION, owner: Scope, name: string, enclosing_scope: Scope) is | |
| 447 | super.init(location, span, owner, name, enclosing_scope); | |
| 448 | ||
| 449 | state_machine = STATE_MACHINE(self); | |
| 450 | si | |
| 451 | si | |
| 452 | si |